TW201900413A - Polyimide film and laminate of inorganic substrate - Google Patents

Abstract

The present invention addresses the problem of providing a layered body of a polyimide film and an inorganic substrate, which is useful for high-yield production of flexible electronic devices comprising fine device arrays such as organic EL display elements. This layered body of a polyimide film and an inorganic substrate is obtained by: washing and cleaning a polyimide film and an inorganic substrate sufficiently to remove foreign matter formed of inorganic substances; bonding the polyimide film and the inorganic substrate together to construct a layered body; subjecting the layered body to a heat treatment at a temperature of at least 350 DEG C but less than 600 DEG C and then to rapid cooling to carbonize and shrink organic foreign matter. By the rapid cooling of the air inside of blisters, blister height is reduced. The number density of blister defects containing carbides is 50 counts/square meter or less, the average blister height is 2 [mu]m or less, and the product of the number density of blisters (counts/square meter) and the average height of the blisters ([mu]m) is 20 or less.

Description

Laminated body of polyimide film and inorganic substrate

The present invention relates to a laminated body of a polyimide film and an inorganic substrate such as glass. More specifically, the present invention relates to a laminated body of a polyimide film and an inorganic substrate. The inorganic polyimide film is temporarily supported on the inorganic substrate, and after the functional elements such as electronic devices are manufactured and processed on the polyimide film, the polyimide film is peeled from the inorganic substrate for manufacturing. A polyimide film is used as a flexible functional element of the substrate.

In recent years, in order to reduce the weight, miniaturization, thinness, and flexibility of functional elements such as semiconductor elements, MEMS elements, display elements, and wearable sensors, people have actively developed methods to form these elements on polymer films. technology. That is, as a base material of electronic parts such as information communication equipment (broadcasting equipment, mobile radio, mobile communication equipment, etc.), radar, high-speed information processing equipment, etc., conventionally, it is heat-resistant and can also handle information communication equipment Ceramics with high frequency (up to GHz band) in the signal frequency band, but ceramics are not flexible and difficult to be thinned, so there is a disadvantage that the applicable field is limited. Therefore, polymer films have recently been used as substrates.

When forming a functional element on the surface of a polymer film, it is desirable to process it by a so-called roll-to-roll process that can be flexible by utilizing the characteristics of the polymer film. However, in the semiconductor industry, the MEMS industry, the display industry and other industries, processing technologies have been constructed that target rigid flat substrates such as wafers or glass substrates. Therefore, in order to form a functional element on a polymer film using the existing basic structure, some people use the following process: bonding the polymer film to a rigid support made of an inorganic substance such as a glass plate, a ceramic plate, a silicon wafer, a metal plate, etc. , And the desired element is formed thereon, and then peeled from the support.

On the other hand, when a conductive material, an insulator material, a semiconductor material, or the like used for a functional element is formed into a polymer film, a vacuum thin film method or a thick film method is often used for heating in a forming process. Generally, these materials exhibit good characteristics when subjected to high temperature processing. Therefore, heat resistance is required in a state where a polymer film is bonded to a support made of an inorganic substance. However, in many cases, when a polymer film is attached to a support using an adhesive material, the heat resistance of the adhesive material is low, which often causes inconvenience in steps.

Due to the lack of a heat-resistant adhesion method for attaching a polymer film to an inorganic substrate, the following technology is known in this application: a polymer solution or a polymer precursor solution is coated on an inorganic substrate and dried on a support. , Harden into a film, and use it for this purpose. Further, in order to facilitate peeling, a technique of forming a plurality of layers and using a part of the layers as a sacrificial layer, or a technique of functionally separating the adhesion / peeling function from the film physical properties has been proposed (Patent Documents 1 to 3). The polymer film obtained by this method is brittle and easily broken, so functional elements formed on the surface of the polymer film are often destroyed when they are peeled from the support. In particular, it is extremely difficult to peel a large-area film from a support, and an industrially practical yield cannot be obtained at all. In view of this situation, as a laminate of a polymer film and a support for forming a functional element, it has been proposed that a polyimide film having excellent heat resistance, a toughness, and a thin film can be bonded by a silane coupling agent. A laminated body formed on a support (inorganic layer) made of an inorganic substance (Patent Documents 4 to 5).

The polymer film surfaces of these laminates actually have various disadvantages, and the production yield of functional devices is low. When the polymer film itself has flaws such as scratches, it is necessary to improve the quality of the polymer film. When foreign matter adheres to the surface of the polymer film, the steps of cleaning can be performed simultaneously with the cleaning of the surface of the polymer film. However, even if a high-quality polymer film is used and further cleaning is performed, defects often remain on the polymer film surface, and the yield of functional element manufacturing cannot be improved. [Prior Art Literature] [Patent Literature]

[Patent Document 1] JP 2016-120629 [Patent Document 2] JP 2016-120630 [Patent Document 3] JP Patent 4834758 [Patent Document 4] JP 2010-283262 [ Patent Document 5] Japanese Patent Application Laid-Open No. 2011-11455

[Problems to be Solved by the Invention]

As a result of diligent research by the present inventors to improve the production yield, it was found that one of the reasons for the low production yield of the functional element is the blister. When a polymer film is bonded to an inorganic substrate with a smooth and rigid surface (hereinafter, a glass plate is used as a representative example of the inorganic substrate will be described.) When a foreign substance is sandwiched between the polymer film and the glass plate As a part of the polymer film with a foreign object as a pillar, the polymer film floats from the glass plate into a tent shape, a gap is generated between the polymer film and the glass plate, and a defect that the surface of the film becomes convex is generated. Such a defect is a blister defect (sometimes also referred to as a blister, or bubble, bulge, bubble.). When the polymer film and the inorganic substrate are bonded through a relatively thick adhesive layer, foreign matter is buried in the adhesive material layer, so it is relatively difficult to generate a blister. However, when the adhesive material layer is thin, especially when the height of the foreign material is larger than the adhesive material layer, a blister may be generated.

The inventors of the present case have been able to reduce the blister by cleaning (washing) the surface of the polymer film and the glass plate (inorganic substrate) before lamination. However, even if the washing is performed carefully, the generation of blister cannot be prevented. [Means for solving problems]

As a result of intensive research in order to solve the aforementioned problems, the inventors of the present case have found a prescription, even when the adhesive layer is thin in a laminate of a polymer film and a support made of an inorganic substance, or the adhesive layer is substantially In the absence of such a situation, the generation of blister can be suppressed, and a high manufacturing yield can be achieved, and the present invention has been completed.

That is, the present invention has the following constitutions. [1] A laminated body of a polyimide film and an inorganic substrate, characterized in that the laminated body of a polyimide film and an inorganic substrate satisfies at least the conditions (a) or (b); (a The number density of blister defects is less than 50 per square meter, the average height of the blister is less than 2 μm, and the product of the number density of blister (number / square meter) and the average height of the blister (μm) is less than 20 (B) In a laminate of a polyfluorene film and an inorganic substrate, the number of blister having a height of 3 μm or more is 10 per square meter or less. [2] The laminate of the polyimide film and the inorganic substrate according to [1], whose area is 0.157 square meters or more. [3] The laminated body of the polyimide film and the inorganic substrate according to [1] or [2], wherein the inside of the blister includes carbide particles. [4] The laminated body of a polyimide film and an inorganic substrate according to any one of [1] to [3], wherein a silane having a thickness of 5 nm to 500 nm exists between the polyimide film and the inorganic substrate. Coupling agent condensate layer. [5] A method for manufacturing a laminated body of a polyimide film and an inorganic substrate according to any one of [1] to [4], characterized in that a polyimide film and an inorganic substrate are laminated After the heat treatment, heat treatment is performed at a temperature of 350 ° C or more and less than 600 ° C. [6] The method for manufacturing a polyimide film and an inorganic substrate laminated body as described in [5], after the polyimide film and the inorganic substrate are made into a laminated body, the temperature is higher than 350 ° C and lower than 600 ° C. The heat treatment is performed at a temperature, and after the heat treatment, the temperature is cooled to at least 200 ° C at a rate of 10 ° C / minute or more and 90 ° C / minute or less. [7] The method for producing a laminated body of a polyimide film and an inorganic substrate according to [5] or [6], wherein, as a step before laminating the polyimide film and the inorganic substrate, ozone is used in advance. The treated ultrapure water cleans the polyimide membrane.

In the present invention, it is preferable to further have the following constitution. [8] The method for producing a laminated body of a polyimide film and an inorganic substrate as described in [6] or [7], wherein the cooling is performed by laminating the polyimide film and the inorganic substrate The inorganic substrate side of the body is cooled by contacting a metal plate having a temperature of 180 ° C or lower. [Effect of the invention]

There are many kinds of foreign materials that cause blister. A foreign substance is an inorganic substance or organic substance existing in the environment, and is attached to a film or an inorganic substrate by static electricity or the like. Inorganic substances can generally be removed relatively easily by washing or the like. Among the types of organic foreign matter adhering to the surface of the polyimide film, the characteristic substance is polyimide particles. It is presumed that the polyfluorene imine particles are generated in a manufacturing process or a cutting process of a polyfluorine film. Foreign matter caused by the polyfluorene imine can be relatively easily removed by washing in the same manner as the inorganic matter. However, since the adhesive, organic foreign matter from the environment, and foreign matter from the living body are relatively soft, and depending on the situation, it is difficult to completely remove it by a simple washing treatment. On the other hand, it is considered that such a flexible and adhesive organic substance has a lower heat resistance than a polyimide film and an inorganic substrate used in the present invention, and can be made by using a high-temperature pretreatment. It is removed by thermal decomposition. However, it is not realistic to set such a previous processing step in the actual step, because heating to cooling will lead to a prolonged manufacturing time, and there is a high risk of new foreign matter adhering or scarring due to operation.

The present invention is characterized in that by bonding the film to the inorganic substrate and performing heat treatment under predetermined conditions, the height of the blister can be reduced even if there is an organic foreign matter between the film and the inorganic substrate, and it can be improved in practical use. No problem level. That is, the effect of the present invention is that even if the blister has a foreign substance inside, when the foreign substance inside is a carbide, the height of the blister is still low, which can suppress the reduction of the production capacity to the minimum, and it can also become a problem. The height of the organic foreign body inner blister is transformed into a carbide foreign body inner blister by a specific processing method, and the height of the blister is reduced to a level without problems.

In the present invention, in particular, the effect of the present invention can be made more significant by controlling the cooling rate after the heat treatment within a predetermined range. That is, by cooling at a specific speed, the blister that has been expanded by the decomposition gas of organic matter can be rapidly contracted. When the cooling rate is longer than necessary, the elastic modulus of the polyimide film, which has been reduced at a high temperature, is restored to the original value before the blister is fully contracted, and the shape retention of the polyimide film itself is improved. In some cases, the height of the blister cannot be sufficiently reduced. Large substrates are prone to uneven heating and cooling rates. In the present invention, it is particularly important to reduce unevenness in the cooling rate. Therefore, in the present invention, it is desirable to cool the laminate by directly contacting the laminate with a substance having a high specific heat, for example, directly contacting a metal plate or the like during cooling.

In addition, in a particularly preferred aspect of the present invention, a sufficient effect can be obtained by cleaning the polyimide film before lamination with ultrapure water that has been treated with ozone in advance. That is, the cause of the blister is a decomposed gas generated by an organic foreign substance. The surface of the polyimide is washed with ultra-pure water that has been decomposed and removed by using ozone treatment in advance, and the originally attached organic foreign matter is washed away. At the same time, the organic foreign matter contained in the cleaning solution itself is also treated with ozone. Decomposition occurs and the molecular weight is reduced, so that the re-adhesion of solid matter is suppressed, and as a result, the density of foreign matter can be greatly reduced. The ozone treatment can be performed, for example, by exposing the washing water to ozone-containing clean air generated by an ozone generator or the like. In the present invention, the ozone concentration in the washing water is preferably 3 ppm or more, preferably 6 ppm or more, more preferably 9 ppm or more, and even more preferably 20 ppm or more. The upper limit of the ozone concentration is not particularly limited and is about 200 ppm.

In the laminated body of the present invention, an inorganic substrate is used as a supporting substrate. The inorganic substrate is a plate made of an inorganic substance, and examples thereof include glass plates, ceramic plates, semiconductor wafers, and metal plates. Further, a composite substrate obtained by laminating two or more kinds selected from a glass plate, a ceramic plate, a semiconductor wafer, and a metal plate may be used. Furthermore, a composite body in which one or more materials selected from glass, ceramics, and metals are dispersed in powder form in other inorganic materials or organic materials can be exemplified. Further, a substrate material having a fiber-reinforced composite structure in which a fibrous material selected from glass, ceramic, and metal is compounded in other inorganic materials or organic materials can be exemplified.

The glass plate of the inorganic substrate and the glass-containing substrate material in the present invention can be exemplified by quartz glass, high silica glass (96% silicon dioxide), soda lime glass, lead glass, aluminum borosilicate Glass, borosilicate glass (Pyrex (registered trademark)), borosilicate glass (alkali-free), borosilicate glass (microchip), aluminosilicate glass, etc. In the present invention, those having a median expansion coefficient of 5 ppm / K or less are particularly preferable. If they are commercially available products, "Corning (registered trademark) 7059" and "Corning (registered trademark) 7059", which are made of glass for liquid crystal display elements, should be used. "Corning (registered trademark) 1737", "EAGLE XG", "AN100" manufactured by Asahi Glass Company, "OA10G" manufactured by Japan Electric Glass Company, "AF32" manufactured by SCHOTT, etc. are preferable.

The ceramic plate of the inorganic substrate in the present invention can be exemplified by a ceramic plate made of one or more materials selected from the group consisting of alumina, mullite, aluminum nitride, silicon carbide, silicon nitride, and boron nitride. , Crystallized glass, cordierite, hectorite, Pb-BSG + CaZrO ₃ + Al ₂ O ₃ , crystallized glass + Al ₂ O ₃ , crystallized Ca-borosilicate glass, borosilicate glass + quartz, Ceramics for substrates such as borosilicate glass + Al ₂ O ₃ , Pb + borosilicate glass + Al ₂ O ₃ , glass ceramics, glass ceramics (zerodur) materials; titanium oxide, strontium titanate, calcium titanate, magnesium titanate, oxidation Capacitor materials such as aluminum, magnesium oxide, blockite, BaTi ₄ O ₉ , BaTi ₄ O ₉ + CaZrO ₃ , BaSrCaZrTiO ₃ , Ba (TiZr) O ₃ , PMN-PT, PFN-PFW; PbNb ₂ O ₆ , Pb Piezoelectric materials such as _0.5 Be _0.5 Nb ₂ O ₆ , PbTiO ₃ , BaTiO ₃ , PZT, 0.855PZT-95PT-0.5BT, 0.873PZT-0.97PT-0.3BT, PLZT, etc.

As the metal material constituting the metal plate in the present invention, it includes single element metals such as W, Mo, Pt, Fe, Ni, and Au; such as nickel-chromium alloy (Inconel), Monel, Nimonic (Nimonic ), Carbon copper, Fe-Ni based Hengfan steel alloy, super Hengfan steel alloy and so on. It also includes multilayer metal plates made by adding other metal layers and ceramic layers to these metals. In this case, if the CTE with the entire additional layer is low, Cu, Al, or the like may be used as the main metal layer. The metal used as the additional metal layer is not limited as long as it has characteristics such as strong adhesion to the polyimide film, non-diffusion, good chemical resistance, and heat resistance. Examples include chromium, nickel, and TiN. , Cu containing Mo, and the like are ideal examples.

The semiconductor wafer in the present invention may be a silicon wafer, a silicon carbide wafer, a compound semiconductor wafer, etc. The silicon wafer is obtained by processing single-crystal or polycrystalline silicon on a thin plate, and is doped into n-type or p-type silicon. Including wafers, pure silicon wafers, etc., and also silicon wafers that deposit silicon oxide layers and various films on the surface of silicon wafers. In addition to silicon wafers, germanium, silicon-germanium, and gallium can also be used. -Arsenic, aluminum-gallium-indium, nitrogen-phosphorus-arsenic-antimony, SiC, InP (indium phosphide), InGaAs, GaInNAs, LT, LN, ZnO (zinc oxide), CdTe (cadmium telluride), ZnSe (selenium Semiconductor wafers such as zinc) and compound semiconductor wafers.

The area of the inorganic substrate in the present invention is preferably 0.157 square meters or more. More specifically, a rectangle having a long side of 45 cm or more and a short side of 35 cm or more is preferable.

Such inorganic substrates as a support may be subjected to activation treatments such as UV ozone treatment, vacuum plasma treatment, atmospheric piezoelectric plasma treatment, corona treatment, flame treatment, ITRO treatment, UV ozone treatment, and treatment exposed to active gas. These treatments mainly have a cleaning effect of removing organic pollutants and other attached pollutants on the surface of the inorganic substrate, and an effect of activating the surface of the inorganic substrate and improving the adhesion to the polyimide film.

The polyfluorene imide in the present invention is a polymer formed by a hydrazone bond. Generally speaking, polyimide is obtained as a condensation product of tetracarboxylic dianhydride and diamine. A general method for producing polyimide is known as follows: a polyamic acid (polyimide precursor) solution obtained by reacting a tetracarboxylic dianhydride and a diamine in a solvent is applied to a support, The precursor film is dried and further converted into polyfluorene imine by the reaction of fluorene imine by heating or the action of a catalyst. When the polyfluorene imide is formed into a film, a method of peeling the precursor film from the support and performing the imidization is known. In addition, for the application of coating a support, a method of performing imidization without peeling is also known. In applications where a polyimide film is used as a substrate for a flexible device, research is being conducted to put a precursor solution onto a support and dry it, and a method for performing imidization on the support is being put into practical use.

The tetracarboxylic dianhydride in the present invention is preferably an aromatic tetracarboxylic dianhydride or an alicyclic tetracarboxylic dianhydride. From the viewpoint of heat resistance, an aromatic tetracarboxylic dianhydride is preferred, and from the viewpoint of light transmittance, an alicyclic tetracarboxylic dianhydride is preferred. Tetracarboxylic dianhydride can be used alone or in combination of two or more kinds.

Examples of the aromatic tetracarboxylic acid in the present invention include pyromellitic dianhydride, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, and 4,4'-oxydiphthalic acid dianhydride. Anhydride, 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride, 3,3', 4,4'-diphenylfluorenetetracarboxylic dianhydride, 2,2-bis [4- ( 3,4-dicarboxyphenoxy) phenyl] propionic anhydride and the like. In the present invention, pyromellitic dianhydride is preferably used.

Examples of the alicyclic tetracarboxylic acids in the present invention include cyclobutane tetracarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid, 3,3 ', 4,4'-dicyclohexyl tetracarboxylic acid. Alicyclic tetracarboxylic acids such as carboxylic acids, and their anhydrides. Among these, a dianhydride having two anhydride structures (for example, cyclobutanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3 ', 4 , 4'-Bicyclohexyltetracarboxylic dianhydride, etc.). The alicyclic tetracarboxylic acids may be used alone or in combination of two or more kinds. In the case of alicyclic tetracarboxylic acids, when transparency is important, for example, it is preferably 80% by mass or more of all tetracarboxylic acids, more preferably 90% by mass or more, and even more preferably 95% by mass or more.

The diamines in the present invention are not particularly limited, and aromatic diamines, aliphatic diamines, alicyclic diamines, and the like that are generally used in the synthesis of polyimide can be used. From the viewpoint of heat resistance, aromatic diamines are preferred. Among aromatic diamines, benzo Aromatic diamines of the azole structure. Use with benzo The aromatic diamines of the azole structure can exhibit high heat resistance, high elastic modulus, low thermal shrinkage, and low linear expansion coefficient. Diamines can be used alone or in combination of two or more.

Among the diamines of the present invention, the aromatic diamines include, for example, 2,2'-dimethyl-4,4'-diaminobiphenyl, 1,4-bis [2- ( 4-aminophenyl) -2-propyl] benzene (bisaniline), 1,4-bis (4-amino-2-trifluoromethylphenoxy) benzene, 2,2'-bis (tris (Fluoromethyl) -4,4'-diaminobiphenyl, 4,4'-bis (4-aminophenoxy) biphenyl, 4,4'-bis (3-aminophenoxy) bi Benzene, bis [4- (3-aminophenoxy) phenyl] ketone, bis [4- (3-aminophenoxy) phenyl] sulfide, bis [4- (3-aminophenoxy Phenyl) phenyl] fluorene, 2,2-bis [4- (3-aminophenoxy) phenyl] propane, 2,2-bis [4- (3-aminophenoxy) phenyl]- 1,1,1,3,3,3-hexafluoropropane, m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, m-aminobenzylamine, p-aminobenzylamine, 3,3'-diamine Diphenyl ether, 3,4'-diamino diphenyl ether, 4,4'-diamino diphenyl ether, 3,3'-diamino diphenyl sulfide, 3,3'-diamine Diphenylfluorene, 3,4'-diaminodiphenylfluorene, 4,4'-diaminodiphenylfluorene, 3,3'-diaminodiphenylfluorene, 3,4 '-Diaminodiphenylhydrazone, 4,4'-diaminodiphenylhydrazone, 3,3'-diaminobenzophenone, 3,4'-diamine Benzophenone, 4,4'-diaminobenzophenone, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-di Aminodiphenylmethane, bis [4- (4-aminophenoxy) phenyl] methane, 1,1-bis [4- (4-aminophenoxy) phenyl] ethane, 1, 2-bis [4- (4-aminophenoxy) phenyl] ethane, 1,1-bis [4- (4-aminophenoxy) phenyl] propane, 1,2-bis [4 -(4-aminophenoxy) phenyl] propane, 1,3-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-amino Phenoxy) phenyl] propane, 1,1-bis [4- (4-aminophenoxy) phenyl] butane, 1,3-bis [4- (4-aminophenoxy) benzene Yl] butane, 1,4-bis [4- (4-aminophenoxy) phenyl] butane, 2,2-bis [4- (4-aminophenoxy) phenyl] butane , 2,3-bis [4- (4-aminophenoxy) phenyl] butane, 2- [4- (4-aminophenoxy) phenyl] -2- [4- (4- Aminophenoxy) -3-methylphenyl] propane, 2,2-bis [4- (4-aminophenoxy) -3-methylphenyl] propane, 2- [4- (4 -Aminophenoxy) phenyl] -2- [4- (4-aminophenoxy) -3,5-dimethylphenyl] propane, 2,2-bis [4- (4-amine Phenylphenoxy) -3,5-dimethylphenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl ] -1,1,1,3,3,3-hexafluoropropane, 1,4-bis (3-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 4,4'-bis (4-aminophenoxy) biphenyl, bis [4- (4-aminophenoxy) phenyl] Ketones, bis [4- (4-aminophenoxy) phenyl] sulfide, bis [4- (4-aminophenoxy) phenyl] sulfenyl, bis [4- (4-aminophenylbenzene Oxy) phenyl] fluorene, bis [4- (3-aminophenoxy) phenyl] ether, bis [4- (4-aminophenoxy) phenyl] ether, 1,3-bis [ 4- (4-aminophenoxy) benzylidene] benzene, 1,3-bis [4- (3-aminophenoxy) benzylidene] benzene, 1,4-bis [4- (3-Aminophenoxy) benzylidene] benzene, 4,4'-bis [(3-aminophenoxy) benzylidene] benzene, 1,1-bis [4- (3- Aminophenoxy) phenyl] propane, 1,3-bis [4- (3-aminophenoxy) phenyl] propane, 3,4'-diaminodiphenylsulfide, 2,2 -Bis [3- (3-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, bis [4- (3-aminophenoxy) phenyl] Methane, 1,1-bis [4- (3-aminophenoxy) phenyl] ethane, 1,2-bis [4- (3-aminophenoxy) phenyl] ethane, bis [ 4- (3-Aminophenoxy) phenyl] fluorene, 4,4'-bis [3- (4-aminophenoxy) benzylidene] di Ether, 4,4'-bis [3- (3-aminophenoxy) benzylidene] diphenyl ether, 4,4'-bis [4- (4-amino-α, α-dimethyl Benzyl) phenoxy] benzophenone, 4,4'-bis [4- (4-amino-α, α-dimethylbenzyl) phenoxy] diphenylfluorene, bis [4- {4- (4-Aminophenoxy) phenoxy} phenyl] fluorene, 1,4-bis [4- (4-aminophenoxy) phenoxy-α, α-dimethylbenzyl Phenyl] benzene, 1,3-bis [4- (4-aminophenoxy) phenoxy-α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-amino -6-trifluoromethylphenoxy) -α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-amino-6-fluorophenoxy) -α, α- Dimethylbenzyl] benzene, 1,3-bis [4- (4-amino-6-methylphenoxy) -α, α-dimethylbenzyl] benzene, 1,3-bis [4 -(4-amino-6-cyanophenoxy) -α, α-dimethylbenzyl] benzene, 3,3'-diamino-4,4'-diphenoxybenzophenone 4,4'-diamino-5,5'-phenoxybenzophenone, 3,4'-diamino-4,5'-diphenoxybenzophenone, 3,3 ' -Diamino-4-phenoxybenzophenone, 4,4'-diamino-5-phenoxybenzophenone, 3,4'-diamino-4-phenoxydiphenyl Methanone, 3,4'-diamino-5'-phenoxybenzophenone, 3,3'-diamino-4 , 4'-Diphenoxybenzophenone, 4,4'-Diamino-5,5'-Diphenoxybenzophenone, 3,4'-Diamino-4,5 '-Diphenoxybenzophenone, 3,3'-Diamino-4-benphenoxybenzophenone, 4,4'-Diamino-5-benphenoxybenzophenone Ketone, 3,4'-diamino-4-benphenoxybenzophenone, 3,4'-diamino-5'-biphenoxybenzophenone, 1,3-bis (3 -Amino-4-phenoxybenzyl) benzene, 1,4-bis (3-amino-4-phenoxybenzyl) benzene, 1,3-bis (4-amino- 5-phenoxybenzyl) benzene, 1,4-bis (4-amino-5-phenoxybenzyl) benzene, 1,3-bis (3-amino-4-biphenyl Oxybenzyl) benzene, 1,4-bis (3-amino-4-biphenoxybenzyl) benzene, 1,3-bis (4-amino-5-biphenoxy) Benzamidine) benzene, 1,4-bis (4-amino-5-biphenoxybenzyl) benzene, 2,6-bis [4- (4-amino-α, α-di Methylbenzyl) phenoxy] benzonitrile and some or all of the hydrogen atoms on the aromatic ring of the aromatic diamine are substituted with a halogen atom, an alkyl or alkoxy group having 1 to 3 carbon atoms, and a cyano group Part or all of the hydrogen atoms of the alkyl or alkoxy group are replaced by halogen atoms Carbon atoms, a halogenated alkyl or alkoxy groups derived from aromatic diamines of 1 to 3.

Examples of the aliphatic diamines in the present invention include 1,2-diaminoethane, 1,4-diaminobutane, 1,5-diaminopentane, and 1,6-diamine Hexane, 1,8-diaminooctane and the like. Examples of the alicyclic diamines in the present invention include 1,4-diaminocyclohexane and 4,4'-methylenebis (2,6-dimethylcyclohexylamine).

Benzo Examples of the diamines of the azole structure include 5-amino-2- (p-aminophenyl) benzo Azole, 6-amino-2- (p-aminophenyl) benzo Azole, 5-amino-2- (m-aminophenyl) benzo Azole, 6-amino-2- (m-aminophenyl) benzo Azole, 2,2'-p-phenylene bis (5-aminobenzo Azole), 2,2'-p-phenylenebis (6-aminobenzo) Azole), 1- (5-aminobenzo Zolo) -4- (6-aminobenzo Zolo) benzene, 2,6- (4,4'-diaminodiphenyl) benzo [1,2-d: 5,4-d '] bis Azole, 2,6- (4,4'-diaminodiphenyl) benzo [1,2-d: 4,5-d '] bis Azole, 2,6- (3,4'-diaminodiphenyl) benzo [1,2-d: 5,4-d '] bis Azole, 2,6- (3,4'-diaminodiphenyl) benzo [1,2-d: 4,5-d '] bis Azole, 2,6- (3,3'-diaminodiphenyl) benzo [1,2-d: 5,4-d '] bis Azole, 2,6- (3,3'-diaminodiphenyl) benzo [1,2-d: 4,5-d '] bis Azole and so on.

In the present invention, the polyimide preferably used is a film composed of a condensate of an aromatic tetracarboxylic dianhydride and an aromatic diamine, and more preferably at least one polyimide selected from the following films Imine film structure: (a) Aromatic tetracarboxylic dianhydride and containing at least benzo Film of a condensate of a diamine of an azole skeleton diamine, (b) A film of a condensate of an aromatic tetracarboxylic dianhydride and a diamine containing at least a diamine having an ether bond in the molecule, (c) Aromatic A film of a condensate of tetracarboxylic dianhydride and a diamine containing at least phenylenediamine, and (d) a film of a condensate of biphenyltetracarboxylic dianhydride and an aromatic diamine.

The thickness of the polyimide film in the present invention is not particularly limited, but is preferably 0.5 μm to 200 μm, and more preferably 3 μm to 50 μm. When the thickness is 0.5 μm or less, it is difficult to control the film thickness, and a part of the polyfluoreneimide defect may occur. On the other hand, when it is 200 μm or more, it may take time to produce and it may be difficult to control the uneven thickness of the film. The uneven thickness of the polyimide film must be 5% or less, more preferably 4% or less, and even more preferably 3% or less.

The film of the condensation product of the tetracarboxylic dianhydride and diamine of the present invention, that is, the polyfluorene imide film can be obtained by a solution film forming method. Polyimide solution film formation method is the following method: using stainless steel rolls or endless belts, or polymer films such as PET as long or endless support, coating the precursor of polyimide resin on the support After the solution is dried, it is peeled off from the support to make a polyimide precursor film. It is preferable to hold both ends of the film with a clamp or a pin and transport it, while further applying heat treatment to make the polyimide precursor. A chemical reaction occurs to form polyimide, and a polyimide film is obtained. The polyimide film obtained by this method has a non-uniform film thickness of less than 5%, preferably 3.6% or less, particularly preferably 2.4% or less, and a tensile fracture strength of 90 MPa or more, preferably 180 MPa or more, especially The polyimide film is preferably 350 MPa or more, and more preferably 450 MPa or more.

In the present invention, in order to adjust the properties of the polyimide film, an inorganic substance may be contained in the polyimide, but it is necessary to keep it to the minimum necessary. Generally, when a polymer film is formed, a small amount of inorganic particles called lubricants are added to actively generate tiny convex portions on the surface of the film. When the film and the film or the film and the smooth surface are overlapped, an air layer is sandwiched therebetween. This exhibits the smoothness of the film. In the present invention, the silicon oxide component contained in the polyfluorene imide film should preferably be kept below 6000 ppm, preferably below 4500 ppm, more preferably below 1800 ppm, even more preferably below 900 ppm. When an excessive amount of lubricant is added, the roughness of the film surface may increase, and the peelability of the second polyimide film may be hindered in some cases.

In the present invention, as the method of bonding the inorganic substrate of the support to the polyimide film, known adhesives and adhesives such as silicone resin, epoxy resin, acrylic resin, and polyester resin can be used. However, the preferred adhesive method in the present invention is an adhesive method using an extremely thin adhesive or adhesive layer having a film thickness of 5 μm or less, or an adhesive method that does not substantially use an adhesive or an adhesive. .

The area of the laminated body of the polyimide film and the inorganic substrate in the present invention is preferably 0.157 square meters or more. In addition, in terms of the area of the laminate of the polyimide film and the inorganic substrate, when the sizes of the polyimide film and the inorganic substrate are different, it means the area of the portion where the two overlap. The area of the laminate of the polyimide film and the inorganic substrate is preferably 0.25 square meters or more, particularly preferably 0.46 square meters or more, more preferably 0.62 square meters or more, and even more preferably 0.98 square meters or more.

In the present invention, in a bonding method that does not substantially use an adhesive or an adhesive, a method using a silane coupling agent for bonding can be used. That is, in the present invention, it is preferable to have a silane coupling agent layer between the inorganic substrate and the polyimide film. The silane coupling agent in the present invention refers to a compound that is physically or chemically interposed between an inorganic substrate and a polyimide film and has an effect of improving the adhesion between the two. Preferred specific examples of the silane coupling agent include N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, and N-2- (aminoethyl)- 3-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyl Triethoxysilane, 3-triethoxysilyl-N- (1,3-dimethyl-butylene) propylamine, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane , 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, vinyltris Chlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane , 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropane Methyl methyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3- Methacryloxypropyltriethoxysilane, 3-propenyloxypropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N- (vinylbenzyl)- 2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride, 3-ureidopropyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-mercaptopropylmethyl Dimethoxysilane, 3-mercaptopropyltrimethoxysilane, bis (triethoxysilylpropyl) tetrasulfide, 3-isocyanatepropyltriethoxysilane, gins- (3-trimethoxy (Silylpropyl) isocyanurate, chloromethylphenethyltrimethoxysilane, chloromethyltrimethoxysilane, aminophenyltrimethoxysilane, aminophenylethyltrimethoxysilane, amine Phenylphenylaminomethylphenethyltrimethoxysilane, hexamethyldisilazane and the like.

In addition to the above-mentioned silane coupling agents which can be used in the present invention, n-propyltrimethoxysilane, butyltrichlorosilane, 2-cyanoethyltriethoxysilane, cyclohexyltrichlorosilane , Decyltrichlorosilane, diethoxymethoxydimethylsilane, diethoxydimethylsilane, dimethoxydimethylsilane, dimethoxydiphenylsilane, dimethoxymethyl Phenylsilane, dodecyltrichlorosilane, dodecyltrimethoxysilane, ethyltrichlorosilane, hexyltrimethoxysilane, octadecyltriethoxysilane, octadecyltrimethoxy Silane, n-octyltrichlorosilane, n-octyltriethoxysilane, n-octyltrimethoxysilane, triethoxyethylsilane, triethoxymethylsilane, trimethoxymethylsilane, trimethylsilane Oxyphenylsilane, pentyltriethoxysilane, pentyltrichlorosilane, triethoxymethylsilane, trichlorohexylsilane, trichloromethylsilane, trichlorooctadecylsilane, trichloro Propylsilane, trichlorotetradecylsilane, trimethoxypropylsilane, allyltrichlorosilane, allyltriethoxysilane Allyltrimethoxysilane, diethoxymethylvinylsilane, dimethoxymethylvinylsilane, trichlorovinylsilane, triethoxyvinylsilane, vinyl ginseng (2-methoxy Ethoxy) silane, trichloro-2-cyanoethylsilane, diethoxy (3-glycidoxypropyl) methylsilane, 3-glycidoxypropyl (dimethoxy) Group) methylsilane, 3-glycidoxypropyltrimethoxysilane, and the like.

Further, other alkoxysilanes may be appropriately added to the silane coupling agent, for example, tetramethoxysilane, tetraethoxysilane, and the like may be added. In addition, other alkoxysilanes are appropriately added to the silane coupling agent, for example, the case of adding tetramethoxysilane, tetraethoxysilane, etc., including the case of not adding, can be performed during mixing and heating operations, and Use after a slight reaction.

Among the silane coupling agents, the silane coupling agent preferably used in the present invention is preferably a silane coupling agent having a chemical structure of one silicon atom in each molecular coupling agent. In the present invention, particularly preferred silane coupling agents include N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, and N-2- (aminoethyl) -3 -Aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyl Triethoxysilane, 3-triethoxysilane-N- (1,3-dimethyl-butylene) propylamine, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, aminophenyl Trimethoxysilane, aminophenethyltrimethoxysilane, aminophenylaminomethylphenethyltrimethoxysilane, and the like. When high heat resistance is particularly required during processing, an aromatic group is preferably connected between Si and the amine group. In addition, in the present invention, a phosphorus-based coupling agent, a titanate-based coupling agent, or the like may be used if necessary.

The coating method of the silane coupling agent in the present invention is not particularly limited, and a general wet coating method or a coating method in a vapor phase can be used. The wet coating method is preferably a stock solution or a solvent solution of a silane coupling agent, preferably an alcohol solution, etc., and uses spin coating, capillary coating, bar coating, smearing, die coating, corner wheel coating, screen printing, Gravure printing, inkjet printing, spray coating, spray coating and other methods. In the present invention, as for the coating method of the silane coupling agent, a vapor-phase coating method using a gas phase is preferably used. The vapor-phase coating method is performed by exposing an inorganic substrate to a vaporized silane coupling agent. In other words, the silane coupling agent coating can be treated by a silane coupling agent. Gasification refers to the vapor in which the silane coupling agent is present, that is, the state in which the silane coupling agent in a substantially gas state or the particulate silane coupling agent exists. Exposure means that the organic polymer film is brought into contact with a gas containing the aforementioned vaporized silane coupling agent, or the organic polymer film is brought into contact in a vacuum state.

The vapor of the silane coupling agent can be easily obtained by heating the liquid silane coupling agent to a temperature of 30 ° C to the boiling point of the silane coupling agent. The vapor of the silane coupling agent can also be generated below the boiling point. The state in which the fine particles of the silane coupling agent coexist can also be used. In addition, the operation of increasing the vapor density may be performed by the operation of temperature and pressure. The boiling point of the silane coupling agent varies depending on the chemical structure, and is in the range of about 100 to 250 ° C. However, heating at 200 ° C or higher may cause side reactions on the organic side of the silane coupling agent, which is not preferable.

The thickness of the silane coupling agent layer in the present invention is preferably 5 nm or more, more preferably 9 nm or more, more preferably 18 nm or more, and more preferably 45 nm or more. The upper limit of the film thickness of the silane coupling agent is preferably 500 nm or less, more preferably 390 nm or less, and even more preferably 240 nm or less. The film thickness of the silane coupling agent can be measured by electron microscope observation of the cross section of the laminate.

The environment in which the silane coupling agent is heated may be any one of under pressure, normal pressure, and reduced pressure. To promote the gasification of the silane coupling agent, it is preferably under normal pressure or reduced pressure. Most of the silane coupling agents are classified as flammable liquids, so they are suitable for sealed containers. It is preferred to replace the inside of the container with a passive gas before performing gasification operations. On the other hand, considering the viewpoint of improving production efficiency and reducing the price of production equipment, it is ideal to apply the silane coupling agent in an environment without using a vacuum. For example, the organic polymer film can be placed in the chamber under normal pressure, so that the carrier gas containing the vaporized silane coupling agent can be filled in the chamber at about normal pressure, from the time when the silane coupling agent is deposited to It returns to the state where there is no vaporized silane coupling agent again, and it is performed at about atmospheric pressure.

The following activation treatment may be applied to at least the side of the polyimide film that becomes the polyimide film of the present invention attached to the inorganic substrate: UV ozone treatment, vacuum plasma treatment, atmospheric piezoelectric plasma treatment, corona treatment, Flame treatment, ITRO treatment, acid treatment, alkali treatment, treatment by exposure to active gas, etc. These treatments mainly have the cleaning effect of removing organic pollutants such as organic matter on the surface of the polyimide film, and the effect of activating the surface of the polyimide film and improving the adhesion to the inorganic substrate.

As a method for producing a polyimide / inorganic substrate laminate obtained by laminating an inorganic substrate and a polyimide film with a silane coupling material, it is preferable to apply the inorganic substrate coated with a silane coupling agent and the polyfluorene. The imine film is overlapped, or the inorganic substrate and the polyfluorene imide film coated with a silane coupling agent are overlapped, and the two are laminated by pressing. Alternatively, both the inorganic substrate and the polyfluorene film may be treated with a silane coupling agent. Examples of the pressing method include ordinary pressing under normal temperature in the air or applying heat while applying heat, and pressing in a vacuum. The preferred pressure is 0.5 MPa to 20 MPa, and more preferably 2 to 10 MPa. If the pressure is high, the substrate may be damaged, and if the pressure is low, a non-tight part may be generated. The preferred temperature range is 0 ° C to 550 ° C, and more preferably 10 ° C to 300 ° C. If the temperature is too high, the film and the inorganic substrate may deteriorate. When pressing in a vacuum, the degree of vacuum is sufficient to be a vacuum formed by an ordinary oil rotary pump, and it is sufficient if it is about 10 Torr or less.

Alternatively, it may be laminated for a while, and then the adhesion may be stabilized by heat treatment. The heat treatment temperature at this time is preferably performed in a range of 50 ° C to 550 ° C. More preferably, it is in the range of 100 ° C to 500 ° C. Heat treatment can be used to improve adhesion stability. If it is 50 ° C or lower, the effect of improving the adhesion stability tends to be small, and if it exceeds 550 ° C, the polyimide film tends to be thermally deteriorated.

In addition, the method for producing a laminate of a polyimide film and an inorganic substrate may also employ the following method: a solution obtained by dissolving the aforementioned polyimide or a polyimide precursor in an organic solvent is cast to an inorganic A polyimide film is formed on the substrate by heat treatment. The solvent may be any solvent capable of dissolving polyimide or a precursor of polyimide, and an aprotic polar solvent or the like is preferably used. Examples include: N, N-dimethylformamide, N, N-dimethylacetamide, N, N-diethylacetamide, N, N-dimethylmethoxyacetamide N, N-di-lower alkylcarboxyfluorenamines, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, dimethylsulfinium, dimethylfluorene, 1,3-dimethyl -2-imidazolidinone, γ-butyrolactone, diethylene glycol dimethyl ether, m-cresol, hexamethylphosphamidamine, N-ethylfluorenyl-2-pyrrolidone, ethylcythreon acetate , Diethylene glycol dimethyl ether, cyclobutane, p-chlorophenol, etc. The solvent may be a mixture of two or more kinds.

The conditions for the heat treatment for making the polyfluorene imide precursor sulfonimide are not particularly limited. The temperature is at least 150 ° C to 200 ° C, more preferably 160 ° C to 190 ° C, and the heat treatment is more than 10 minutes, preferably It is preferably 30 minutes or more, particularly preferably 60 minutes or more, and then heat treatment is preferably performed in a temperature range of 400 ° C to 550 ° C, preferably 430 ° C to 530 ° C, and more preferably 460 ° C to 530 ° C. In addition, the time for which the heat treatment is performed at a temperature of 200 ° C. or higher (including the time for which the heat treatment is performed at the highest temperature) can be appropriately determined and is not particularly limited. By this treatment, the solvent can be evaporated to form a polyimide, and a good polyimide / inorganic substrate laminate can be produced.

Alternatively, the following method may also be used: a solution obtained by dissolving the aforementioned polyimide or polyimide precursor in an organic solvent is coated on an inorganic substrate, and partially dried as appropriate, and a polyfluorene is laminated thereon The imine film is then dried. Alternatively, a known method may be adopted in which a solution obtained by dissolving the aforementioned polyimide or polyimide precursor in an organic solvent is coated on an inorganic substrate, and partially dried as appropriate, and further, different types A solution obtained by dissolving polyimide or a polyimide precursor in an organic solvent is coated on an inorganic substrate, and then dried.

The blister in the present invention refers to a laminate of a polyimide film and an inorganic substrate, and a gap is generated between the polyimide film and the inorganic substrate, and the side of the polyimide film bulges into a tent shape, or Disadvantage of dome-like shape. The blister of the present invention refers to a size that can be confirmed with the naked eye. More specifically, it refers to a blister having a diameter of 50 μm or more when the blister viewed in a planar direction is round. In addition, the diameter here is an average value of the long diameter and the short diameter when the blister is deformed.

In the laminate of the polyimide film and the inorganic substrate of the present invention, the number of the blister having a height of 3 μm or more is preferably 10 or less per 1 square meter, more preferably 7 or less, and particularly preferably 4 or less. It is even better for 2 or less. 0 is even better. In the present invention, further, the number of blister having a height of 2.2 μm or more is preferably 10 or less per 1 square meter, more preferably 7 or less, even more preferably 4 or less, and even more preferably 2 or less. 0 is even better. In the present invention, further, the number of the blister having a height of 1.4 μm or more is preferably 10 or less per 1 square meter, more preferably 7 or less, more preferably 4 or less, even more preferably 2 or less. 0 is even better. In the present invention, further, the number of the blister having a height of 0.8 μm or more is preferably 10 or less per 1 square meter, more preferably 7 or less, particularly preferably 4 or less, and even more preferably 2 or less. 0 is even better. The number density of the total number of blister in the present invention is preferably 50 pieces / square meter or less.

The height of the blister in the present invention can be measured using a 3D laser microscope. The average value of the height of the shortcomings of the blister in the present invention is preferably 2 μm or less, more preferably 1.6 μm or less, even more preferably 1.2 μm or less, and even more preferably 0.8 μm or less. If the average value of the height of the defect part of a blister exceeds this range, manufacturing capacity will fall significantly.

In the present invention, the product of the number density of the blister (number / square meter) and the average height of the blister (μm) is preferably 20 or less. The height of the blister is an important factor that determines the quality of the laminated body of the present invention. When there are many blisters with a low height, the average value of the calculated blister height is low. However, by calculating the product of the average height of the blister and the distribution of the number of blister, it can be an effective parameter for improving the productivity of flexible device manufacturing.

The blister in the present invention particularly relates to a blister in which carbide particles (carbide foreign matter) are enclosed in the gap. Carbide refers to the case where the carbide is black or black-brown and satisfies the total of C and O elements in the SEM-EDX to more than 50% of all elements, or in the case where a spectrum specific to carbides is present in micro-IR analysis Substances with at least any of the conditions. When a glass plate is used as the inorganic substrate, the color of the foreign matter (particles) contained in it can be easily identified by looking from the glass plate side. In the case of an opaque inorganic substrate, the film side can be cut and observed.

The laminated body of the polyimide film and the inorganic substrate of the present invention can be obtained by making the polyimide film and the inorganic substrate into a laminated body, and then performing a heat treatment at a temperature of 350 ° C. to 600 ° C. The lower limit of the heat treatment temperature is preferably 370 ° C or higher, more preferably 390 ° C or higher, and even more preferably 420 ° C or higher. The upper limit of the heat treatment temperature is preferably 560 ° C or lower, more preferably 520 ° C or lower, even more preferably 490 ° C or lower, and even more preferably 460 ° C or lower. When the heat treatment temperature is not within a predetermined range, carbonization of foreign substances may not be sufficiently performed. If the heat treatment temperature is above the predetermined range, the polyimide film may be easily deteriorated, and the flexible device may be peeled from the substrate. Problems such as film breakage occur. The heat treatment time can be maintained for 5 seconds or more after heating and reaching a predetermined temperature, preferably for 30 seconds or more, and even more preferably for 100 seconds or more before cooling. If the holding time is longer than necessary, the polyimide film is liable to deteriorate. Regarding the heating rate, heating is preferably performed at a heating rate of 5 ° C / minute to 200 ° C / minute. In addition, when the temperature is raised at a rate of 200 ° C./min or more, the number of blister may increase.

In the present invention, after the polyimide film and the inorganic substrate are made into a laminate, heat treatment is performed at a temperature of 350 ° C to 600 ° C. Cool down to at least 200 ° C. The cooling rate is preferably 15 ° C / min or more, particularly preferably 25 ° C / min or more. The upper limit of the cooling rate is preferably 80 ° C / min or less, more preferably 70 ° C / min or less, and even more preferably 60 ° C / min or less. [Example]

Hereinafter, the present invention will be described more specifically with examples and comparative examples, but the present invention is not limited to the following examples. In addition, the evaluation methods, processing methods, operation methods, and the like of the physical properties in the following examples are as follows.

＜ Reduction viscosity of polyamidic acid (ηsp / C) ＞ The polymer is dissolved in N-methyl-2-pyrrolidone (or N, N-dimethylacetamide) to make the polymer concentration 0.2 g / dl. The solution was measured using an Ubbelohde-type viscosity tube at 30 ° C. (The solvent used in the preparation of the polyfluorinated acid solution was N, N-dimethylacetamide. Phenamine dissolves the polymer and measures it.)

<Film thickness of polyimide film> The polyimide film was obtained by observing the SEM cross section of the cross section of the laminate. In addition, unless otherwise stated, an average value of film thicknesses of 5 points randomly selected in a region 1 mm or more inside from the end of each polyimide film is used as the film thickness of the polyimide film. As for the second polyimide film, an arithmetic average of 10 points was randomly selected from the polyimide film before lamination or the film after the second polyimide film was peeled 90 degrees from the laminate. Value as the film thickness. In addition, the film thickness unevenness [%] was calculated from the maximum, minimum, and arithmetic mean of the film thickness at any 10 points according to the following formula. Film thickness unevenness = 100 × (maximum value-minimum value) / arithmetic average value [%] In addition, the thickness of the polyimide film of the second polyimide film is measured by a stylus film thickness meter . In addition, when the film can be peeled well, the film thickness and film thickness unevenness of the polyimide film after peeling are almost the same as the film thickness and film thickness unevenness of the polyimide film before lamination.

<Thermal decomposition temperature> A polyimide film (polyimide film) peeled from the laminate was used as a sample, and after drying at 150 ° C for 30 minutes, the thermogravimetric measurement (TGA) was performed under the following conditions. The temperature at which the sample mass was reduced by 5% was taken as the thermal decomposition temperature. Device name: TG-DTA2000S plate manufactured by MAC science company: Aluminum plate (non-air-tight type) Sample mass: 10mg Heating start temperature: 30 ° C Heating rate: 20 ° C / min Environment: Argon

<Linear expansion coefficient> For a sample obtained in the form of a polyimide film (film), the stretch ratio is measured under the following conditions, and the stretch ratio at intervals of 30 ° C to 45 ° C, 45 ° C to 60 ° C, ... at 15 ° C is measured. This temperature was measured at 300 ° C, and the average value of all measured values was calculated as CTE. Device name: MAC science company TMA4000S Sample length: 20mm Sample width: 2mm Heating start temperature: 25 ° C Heating end temperature: 400 ° C Heating speed: 5 ° C / min Environment: Argon

<Number of blister defects> Count the number of blister that can be confirmed with the naked eye. The size of the detectable blister is 50 μm or more in terms of average diameter. <Measurement of height of blister defect> The height of the blister part (convex defect) of a laminate of a polyimide film and an inorganic substrate is measured using the height measurement function of a color 3D laser microscope VK9710 manufactured by Keyence.

<Thickness of Silane Coupling Agent Layer> The thickness was measured using an electron microscope photograph of a cross section of a laminated body of a polyimide film and an inorganic substrate.

<Foreign matter analysis> The polyimide film of the blister part containing the foreign matter was cut open, and the micro IR measurement of the foreign matter was performed. The absorption of the obtained IR spectrum was smooth and broad as a whole, and it was not confirmed in the region of 1000-3500 cm ^-1 The characteristic absorption from the resin was confirmed to be a carbide.

<Manufacturing example> [Production of polyimide precursor (polyamic acid) solution PV1] Nitrogen substitution was performed in a reaction vessel equipped with a nitrogen introduction tube, a thermometer, and a stirring rod, and then 5-amino-2 was added. -(P-aminophenyl) benzo 223 parts by mass of azole and 4,416 parts by mass of N, N-dimethylacetamidamine were completely dissolved, and then 217 parts by mass of pyromellitic dianhydride was added and stirred at a reaction temperature of 25 ° C for 24 hours to obtain a brown and viscous Polyfluorinated acid solution [PV1].

[Manufacturing of Polyimide Precursor (Polyamidine) Solution PV2] The reaction vessel equipped with a nitrogen introduction tube, a thermometer, and a stirring rod was replaced with nitrogen, and then 3,3 as tetracarboxylic dianhydride 398 parts by mass of ', 4,4'-biphenyltetracarboxylic dianhydride, 132 parts by mass of p-phenylenediamine, and 30 parts by mass of 4,4'-diaminodiphenyl ether were dissolved in 4,600 parts by mass of N, N- Dimethylacetamide was stirred at a reaction temperature of 25 ° C. for 24 hours to obtain a brown and viscous solution of polyamidic acid [PV2].

[Production of polyimide precursor (polyamic acid) solution PV3] The reaction vessel equipped with a nitrogen introduction tube, a thermometer, and a stirring rod was replaced with nitrogen, and then 545 parts by mass of pyromellitic anhydride, 4 500 parts by mass of 4'-diaminodiphenyl ether was dissolved in 8,000 parts by mass of N, N-dimethylacetamidamine, and the same reaction was performed while keeping the temperature below 20 ° C to obtain polyamidoamine Acid solution [PV3]. [Production of polyimide precursor (polyamic acid) solution PV4] Nitrogen substitution was performed in a reaction vessel equipped with a nitrogen introduction tube, a thermometer, and a stirring rod, and then 545 parts by mass of pyromellitic dianhydride, 153 parts by mass of p-phenylenediamine and 200 parts by mass of 4,4'-diaminodiphenyl ether are dissolved in 8,000 parts by mass of N, N-dimethylacetamidamine, and the same conditions are maintained at a temperature below 20 ° C. This was reacted to obtain a polyamidic acid solution [PV4].

[Manufacturing of Polyimide Precursor (Polyamino Acid) Solution PV5] Nitrogen substitution was performed in a reaction vessel equipped with a nitrogen introduction tube, a thermometer, and a stirring rod, and then 2, 2 were added to the reaction vessel under a nitrogen atmosphere. 155.9 parts by mass of '-dimethyl-4,4'-diaminobiphenyl and 1200 parts by mass of N, N-dimethylacetamidamine, after dissolving them, directly cooling the reaction vessel in a solid form 142.9 parts by mass of cyclobutanetetracarboxylic dianhydride was added in portions, and the mixture was stirred at room temperature for 5 hours. Thereafter, it was diluted with 1000 parts by mass of N, N-dimethylacetamide to obtain a polyamic acid solution [PV5] having a reduction viscosity of 4.20 dl / g.

[Manufacturing of Polyimide Precursor (Polyamino Acid) Solution PV6] The reaction vessel equipped with a nitrogen introduction tube, a thermometer, and a stirring rod was replaced with nitrogen, and then, 2, 2 was added to the reaction vessel under a nitrogen atmosphere. 176.5 parts by mass of '-bis (trifluoromethyl) -4,4'-diaminobiphenyl and 1200 parts by mass of N, N-dimethylacetamide, after dissolving them, directly cooling the reaction vessel while cooling 122.9 parts by mass of 1,2,4,5-cyclohexanetetracarboxylic dianhydride was added in portions as a solid, and stirred at room temperature for 18 hours. Thereafter, it was diluted with 500 parts by mass of N, N-dimethylacetamide to obtain a polyamic acid solution [PV6] having a reduction viscosity of 3.26 dl / g.

[Production of polyimide precursor (polyamic acid) solution PV7] The reaction vessel equipped with a nitrogen introduction tube, a thermometer, and a stirring rod was replaced with nitrogen, and then 3,3 as a tetracarboxylic dianhydride 398 parts by mass of ', 4,4'-biphenyltetracarboxylic dianhydride and 148 parts by mass of p-phenylenediamine dissolved in 4,600 parts by mass of N, N-dimethylacetamide, and stirred at a reaction temperature of 25 ° C. for 24 Hours, a brown and viscous solution of polyamidic acid [PV7] was obtained.

<Production of Polyimide Film> The polyamic acid solution [PV1] obtained in the production example was defoamed, and then applied to a smooth surface of a polyester film A4100 made by Toyobo Co., Ltd. using a corner wheel coater, and used The continuous dryer was dried at 95 ° C for 5 minutes and 110 ° C for 10 minutes to prepare a polyamine film. Then, the obtained polyamic acid film was peeled from the polyester film, and both ends of the film were used to heat-treat in a continuous heat treatment furnace at 250 ° C for 3 minutes, and then heat-treated at 485 ° C for 3 minutes, and cooled to room temperature to obtain a polymer film. Imine film [PF1a]. The evaluation results of the obtained polyfluoreneimide film are shown in Table 1. The "film formation" in the table indicates that a polyimide film obtained by this method is used. Hereinafter, the polyimide solution, film formation method, coating film thickness, drying, and heat treatment conditions were changed, and the solution was film-formed in the same manner to obtain a polyimide film shown in Table 1. The results are shown in Table 1.

<Inorganic substrate (support)> The substrate [G1] is a glass plate for a liquid crystal display using 370 mm × 470 mm and a thickness of 0.7 mm. The substrate [G2] is a glass plate for a liquid crystal display using 550 mm x 650 mm and a thickness of 0.7 mm.

<UV / ozone treatment> A UV / ozone cleaning and reforming device manufactured by Lantechnical Service was used, the distance between the lamp and the inorganic substrate was set to 30 mm, and the inorganic substrate was subjected to UV / ozone treatment for 1 minute.

〈Silane coupling agent treatment〉 After replacing the chamber of the support table equipped with a heating plate and an inorganic substrate with clean dry nitrogen, the UV / ozone-treated inorganic substrate is set on the support table so that the liquid surface is positioned on the support table. In the manner of 200 mm below the inorganic substrate, a shallow pan filled with a silane coupling agent (3-aminopropyltrimethoxysilane) was placed, and the shallow pan was heated to 100 ° C with a hot plate to expose the lower surface of the inorganic substrate. After the silane coupling agent vapor for 3 minutes, then take it out of the chamber, set it in a clean operation table, and place it on a heating that has been adjusted to 120 ° C so that the side of the inorganic substrate opposite to the exposed surface contacts the hot plate. The plate was subjected to a heat treatment for 1 minute to perform a silane coupling agent treatment.

<Washing Treatment of Film> The obtained polyimide film was washed with a continuous wet film cleaning device, and further dried in a clean and dry air at 120 ° C for 5 minutes while being transported. In addition, the cleaning liquid used in the wet cleaning device is refined by membrane filtration until the resistivity becomes 15 MΩ ･ cm or more, and then the ozone-containing clean air generated by the ozone generator is used to aerate the ozone concentration. It is adjusted to 10 ppm or more.

<Plasma treatment> <Plasma treatment of film> The polyimide film is cut to a size 10 mm smaller than each of the long and short sides of the glass substrate, and the treatment is performed using a single-piece vacuum plasma device. The vacuum plasma processing system adopts the RIE mode using parallel plate electrodes and RF plasma processing. Nitrogen is introduced into the vacuum chamber, and 13.54MHz high-frequency power is introduced. The processing time is 3 minutes.

<Formation of Gas Barrier Layer: Silicon Nitride Film> A gas barrier layer was formed using a conventional plasma CVD apparatus in the following manner. The source gas system uses silane gas (SiH ₄ ), ammonia gas (NH ₃ ), nitrogen gas (N ₂ ), and hydrogen gas (H ₂ ). Regarding the supply amounts of various gases, the silane gas was set to 100 sccm, the ammonia gas was set to 200 sccm, the nitrogen gas was set to 500 sccm, the hydrogen gas was set to 500 sccm, and the film formation pressure was set to 60 Pa. The supplied plasma was set to 3000W at 13.58MHz. During the film formation process, a glass plate (substrate holder) was supplied with a bias power of 500 W at a frequency of 400 kHz.

[Table 1]

The abbreviations in Table 1 are as follows. PMDA: pyromellitic dianhydride, BPDA: 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, CBA: cyclobutanetetracarboxylic dianhydride, CHA: 1,2,4,5- Cyclohexanetetracarboxylic dianhydride, ODA: 4,4'-diaminodiphenyl ether, PDA: phenylenediamine, DAMBO: 5-amino-2- (p-aminophenyl) benzo Azole, BPA: 2,2'-dimethyl-4,4'-diaminobiphenyl, FA: 2,2'-bis (trifluoromethyl) -4,4'-diaminobiphenyl, CTE: coefficient of linear expansion.

<Example 1> The polyimide film [PF1a], which is a polyimide film, was subjected to a plasma treatment, and the silane coupling agent-treated surface of the inorganic substrate treated with the silane coupling agent was superposed. The polyimide film was superimposed, and after temporary compression bonding with a roller laminator, it was installed in a clean operation table, and the inorganic substrate side was brought into contact with the hot plate, and the plate was placed on a heating plate that had been adjusted to 150 ° C, and implemented. The heat treatment was performed for 3 minutes to obtain a laminate of a polyimide film and an inorganic substrate. The obtained laminate of the polyimide film and the inorganic substrate was stored in an environment at a temperature of 20 to 25 ° C. and a relative humidity of 65 ± 30% for more than 12 hours.

The obtained laminate of polyimide film and inorganic substrate was heat-treated in a blunt oven at 450 ° C for 30 minutes. Take it out of the oven, place it on the copper substrate that has been adjusted to a predetermined temperature between 25 ° C and 180 ° C so that the inorganic substrate (glass plate) side is in contact, and quickly cool it to a temperature below 200 ° C. The cooling rate is controlled by the temperature of the copper plate. The average cooling rate when cooling from 450 ° C to 200 ° C was taken as the cooling rate.

The number of blister existing in the obtained laminated body of the polyimide film and the inorganic substrate was counted in steps of each size. Furthermore, the number density was calculated by dividing the total number of blister by the area of the laminate. Furthermore, the height of all the blister was measured with a laser microscope, the average value was calculated | required, and the product of the average height of the blister and the number density was calculated | required. Select any 5 counted blister, cut the polyimide film side, and analyze the foreign particles contained in it. As a result, it was confirmed that all of them were carbide particles. The above results are shown in Table 2. In addition, in Table 2, Table 3, and Table 4, inertness shows the process in the environment substituted with nitrogen. A size of 50 μm to 1 mm means 50 μm or more and less than 1 mm, a size of 1-2 mm means 1 mm to 2 mm, and a size of 2-3 mm means 2 mm to 3 mm.

<Examples 2 to 9 and Comparative Examples 1 to 6> Experiments were performed by appropriately changing the inorganic substrate, the polyimide film, and the respective processing conditions, etc., to obtain Example 2 shown in Tables 2, 3, and 4. ~ A laminate of the polyfluorine film and the inorganic substrate of Example 9 and Comparative Examples 1 to 6. The height distribution of the blister present in each laminate is shown in Table 2, Table 3, and Table 4. In addition, in the same manner as in Example 1, five blisteres were selected for each laminate, and the contents of the blister were analyzed, and it was confirmed that the contents were all carbide particles.

[Table 2]

[table 3]

[Table 4]

<Application Example> The laminated body of the polyimide film and the inorganic substrate obtained in Examples 1 to 9 and Comparative Examples 1 to 6 was dried at 100 ° C for 1 hour, and then installed in a vacuum device for forming a gas barrier layer. And decompressed. After confirming that the predetermined degree of vacuum was reached, a silicon nitride film was formed on the surface of the polyimide film as a gas barrier layer. Then, on the surface of the gas barrier layer of the laminated body, each thin film is vapor-deposited with a degree of vacuum of the order of 10 ^-5 Pa and laminated. First, an anode made of indium tin oxide (ITO) with a film thickness of 100 nm was formed at a film formation temperature of 400 ° C. Then, N, N'-bis (1-naphthyl) -N, N'-diphenylbenzidine) was formed on ITO to a thickness of 30 nm, and 1,3-bis (N -Carbazolyl) benzene. Then, the following compounds 1 and 4,4'-bis (N-carbazolyl) -1,1'-biphenyl were co-evaporated from different evaporation sources to form a layer having a thickness of 20 nm, and a light-emitting layer was prepared. . At this time, the concentration of Compound 1 was 10% by weight. Then, 1,3,5-ginseng (1-phenyl-1H-benzimidazol-2-yl) benzene was formed to a thickness of 40 nm, and lithium fluoride of 0.8 nm was vapor-deposited thereon. Further, ITO was formed in the same manner to form a cathode. A gas barrier layer is further formed thereon. Finally, it was peeled from the glass plate, thereby fabricating a flexible organic EL element. With regard to the obtained organic EL element, the quality of the light-emitting element was visually judged, and when the black point (no light-emitting point) converted to a square of 10 cm on one side was 1 or less, it was evaluated as ◎, when it was 3 or less, it was evaluated as ○ and as 4 In the above case, it was evaluated as ×. The results are shown in Tables 2, 3 and 4. From the results, it can be seen that a good device can be produced by using the laminate of the polyfluorene imide film and the inorganic substrate of the present invention. [Chemical 1] [Industrial availability]

As described above, the laminated body of the present invention is ideally used as a substrate for manufacturing flexible electronic devices such as flexible display elements. The present invention can be widely used in various flexible electronic devices, MEMS elements, sensor elements, solar cells, wearable elements, and the like.

1‧‧‧ inorganic substrate

2‧‧‧Polyimide film

3‧‧‧ Foreign matter (carbide particles)

h‧‧‧ height of blister (convex height)

w‧‧‧ blister size (blister diameter)

[Fig. 1] Fig. 1 is a schematic explanatory view of a blister in a laminated body of a polyimide film and an inorganic substrate according to the present invention.

Claims (7)

A laminated body of a polyimide film and an inorganic substrate, characterized in that, in the laminated body of the polyimide film and an inorganic substrate, at least the conditions (a) or (b) are satisfied; (a) a blister (blister) The number density of defects is less than 50 per square meter, the average height of the blister is less than 2 μm, and the product of the number density of the blister (number / square meter) and the average height of the blister (μm) is less than 20 (B) In a laminate of a polyfluorene film and an inorganic substrate, the number of blister having a height of 3 μm or more is 10 per square meter or less. For example, the laminated body of polyimide film and inorganic substrate with the scope of patent application No. 1 has an area of 0.157 square meters or more. For example, the laminated body of a polyimide film and an inorganic substrate in the scope of application for the patent item 1 or 2, wherein the inside of the blister contains carbide particles. For example, a laminated body of a polyimide film and an inorganic substrate in the scope of application for the patent item 1 or 2, wherein a silane coupling agent condensate layer having a thickness of 5 to 500 nm exists between the polyimide film and the inorganic substrate. . A method for manufacturing a laminated body of a polyimide film and an inorganic substrate according to any one of claims 1 to 4 in the scope of application for a patent, characterized in that: after the polyimide film and the inorganic substrate are made into a laminated body , Heat treatment at a temperature of 350 ° C or more and less than 600 ° C. For example, the method for manufacturing a laminated body of a polyimide film and an inorganic substrate according to item 5 of the patent application scope is that after the polyimide film and the inorganic substrate are made into a laminated body, the temperature is higher than 350 ° C and less than 600 ° C. The heat treatment is performed at a temperature, and after the heat treatment, the temperature is cooled to at least 200 ° C at a rate of 10 ° C / minute or more and 90 ° C / minute or less. For example, a method for manufacturing a laminated body of a polyimide film and an inorganic substrate according to item 5 or 6 of the scope of the patent application, wherein, as a step before laminating the polyimide film and the inorganic substrate, treatment with ozone in advance is used. The ultra-pure water was used to wash the polyimide membrane.